The present invention relates to a novel hyperbranched compound having a tetrafunctional central group. The present invention additionally relates to a novel process for preparing hyperbranched compounds. The present invention further relates to the use of the novel hyperbranched compound as a functional component in multisubstance mixtures and for preparing dendrimers of higher generations.
Hyperbranched compounds and dendrimers containing a tetrafunctional central group are known from the patent WO 93/17060. The central group used is a tetrol such as pentaerythritol, ditrimethylolpropane, diglycerol and ditrimethylolethane. However, the corresponding hyperbranched compounds are too viscous and too poorly soluble for numerous end uses. For example, it is impossible to prepare particularly high-solids coating compositions, adhesives or sealing compounds in solution or dispersion in aqueous or organic media using the known hyperbranched compounds. Additionally, the liquid coating compositions, adhesives or sealing compounds which comprise the known hyperbranched compounds as functional components are too viscous for the majority of application technologies. Accordingly, powder coating materials and powder slurries comprising known hyperbranched compounds have film formation temperatures which in many cases are too close to the crosslinking temperature.
It is an object of the present invention to find novel hyperbranched compounds which no longer have the disadvantages of the prior art and which make it possible to prepare new coating compositions, adhesives and sealing compounds which have advantageously low viscosities even at high solids content or in the melt. A further object of the present invention is to find a novel process for preparing hyperbranched compounds which allows such compounds to be obtained in a particularly simple way. Another object of the present invention is to find novel end uses for hyperbranched compounds, especially as functional components in multisubstance mixtures and for preparing dendrimers of higher generations.
Accordingly, we have found the novel hyperbranched compounds having a tetrafunctional central group of the general formula I
C[xe2x80x94Aqxe2x80x94Xxe2x80x94]m[xe2x80x94Arxe2x80x94Xxe2x80x94]n[xe2x80x94Asxe2x80x94Xxe2x80x94]o[xe2x80x94Atxe2x80x94Xxe2x80x94]pxe2x80x83xe2x80x83(I),
in which the indices and variables have the following meanings:
xe2x80x83m+n+o+p=4; where
m=an integer from 1 to 3 and
n, o and p=0 or an integer from 1 to 3;
q, r, s and t=an integer from 1 to 5, where q greater than r, s, t;
X=xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94or xe2x80x94NHxe2x80x94;
A=xe2x80x94CR2xe2x80x94; where
R=xe2x80x94H, xe2x80x94F, xe2x80x94Cl, xe2x80x94Br, xe2x80x94CN, xe2x80x94NO2, C1-C3 alkyl or C1-C3 haloalkyl or C1-C3 alkoxy radical or,
xe2x80x83if q, r, s and/or t=at least 2, a C2-C4 alkanediyl and/or C2-C4 oxaalkanediyl radical which bridges 2 to 5 carbon atoms, and/or an oxygen atom xe2x80x94Oxe2x80x94, which bridges 3 to 5 carbon atoms, of the radical xe2x80x94Axe2x80x94.
In the text below, the novel hyperbranched compounds having a tetrafunctional central group of the general formula I are referred to for brevity as xe2x80x9ccompounds of the inventionxe2x80x9d.
The tetrafunctional central groups of the general formula I are referred to below for brevity as xe2x80x9ccentral groups Ixe2x80x9d.
Accordingly, the novel process for preparing the compounds of the invention is referred to below as the xe2x80x9cprocess of the inventionxe2x80x9d.
Similarly, in the text below, the novel multisubstance mixtures which comprise the compounds of the invention are referred to as xe2x80x9cmultisubstance mixtures of the inventionxe2x80x9d, in particular as xe2x80x9ccoating compositions of the inventionxe2x80x9d, xe2x80x9cadhesives of the inventionxe2x80x9d, or xe2x80x9csealing compounds of the inventionxe2x80x9d.
The novel dendrimers of higher generations which can be prepared using the compounds of the invention are referred to below as xe2x80x9cdendrimers of the inventionxe2x80x9d
In the light of the prior art it is surprising that the object of the present invention was able to be achieved with the aid of the compounds of the invention. In particular, it was not expected that varying the central group, sometimes referred to as an initiator group in the prior art, would have such far-reaching technical consequences.
The essential constituent of the compounds of the invention is the central group I.
In the general formula I, the indices m, n, o and p add up to 4. The index m is always larger than 0 and stands for an integer from 1 to 3, in particular 1.
While observing the above boundary condition, the indices n, o and p have the value 0 or represent an integer from 1 to 3. This means that it is not possible for each of these indices to adopt the value 0.
In accordance with the invention, the following combinations of values in the indices are of advantage:
m=1 and n, o, p=1;
m=1, n=2, o, p=1;
m=1, n=2, o=1 and p=0;
m=1, n=3, o, p=0;
m=2, n=1, o=1 and p=0;
m=2, n=2 and o, p=0;
m=3, n=1 and o, p=0.
Of these, particular advantage is possessed by those numerical combinations in which m=1.
In the general formula I, the indices q, r, s and t denote integers from 1 to 5. In this case the index q is always larger than the indices r, s and t. Accordingly, the index q has a value of at least 2.
In accordance with the invention, the following numerical combinations of the indices are of advantage:
q=2, r, s and/or t=1;
q=3, r, s and/or t=1 and/or 2;
q=4, r, s and/or t=1, 2 and/or 3;
q=5, r, s and/or t=1, 2, 3 and/or 4.
The variable xe2x80x94Xxe2x80x94 in the general formula I denotes divalent oxygen atoms xe2x80x94Oxe2x80x94 or sulfur atoms xe2x80x94Sxe2x80x94 or a secondary amino group xe2x80x94NHxe2x80x94. In accordance with the invention it is advantageous if xe2x80x94Xxe2x80x94 is xe2x80x94Oxe2x80x94.
The variable xe2x80x94Axe2x80x94 in the formula I denotes a divalent radical xe2x80x94CR2xe2x80x94.
The radical R therein represents hydrogen atoms xe2x80x94H, fluorine atoms xe2x80x94F, chlorine atoms xe2x80x94Cl, bromine atoms xe2x80x94Br, nitrile groups xe2x80x94CN, nitro groups xe2x80x94NO2, C1-C3 alkyl or C1-C3 haloalkyl groups or C1-C3 alkoxy groups. Examples of suitable groups of this kind are methyl, ethyl, propyl, trifluoromethyl, trichloromethyl, perfluoroethyl, perfluoropropyl, methoxy, ethoxy or propoxy groups.
Of advantage in accordance with the invention are hydrogen atoms or methyl groups, which are therefore used for preference. In particular, hydrogen atoms are used. Accordingly, the variables xe2x80x94Axe2x80x94 particularly preferred in accordance with the invention comprise methylene groups.
If in the general formula I at least one of the indices q, r, s and/or t represents at least the number 2, the radical R may also represent a C2-C4 alkanediyl radical and/or oxaalkanediyl radical which cyclically bridges from 2 to 5 carbon atoms of the radical xe2x80x94Axe2x80x94. Alternatively, the radical xe2x80x94Rxe2x80x94 may represent an oxygen atom xe2x80x94Oxe2x80x94 which cyclically bridges from 3 to 5 carbon atoms of the radical xe2x80x94Axe2x80x94. Formed as a result are cyclopentane-1,2- or 1,3-diyl groups, tetrahydrofuran-2,3-, -2,4-, -2,5- or -3,4-diyl groups, cyclohexane-1,2-, -1,3- or -1,4-diyl groups, or tetrahydropyran-2,3-, -2,4-, -2,5- or -2,6-diyl groups, but not epoxide groups.
Examples of central groups I which are especially advantageous in accordance with the invention are derived formally, therefore, from the tetrols (III1) to (III10) described below by abstracting the four hydrogen atoms of the hydroxyl groups.
Of these, the central group I which derives from the tetrol (III1) (2,2-bishydroxymethyl-1,4-butanediol; homopentaerythritol) is very particularly advantageous and is therefore used with very particular preference in accordance with the invention.
In the compounds of the invention, the above-described variables xe2x80x94Xxe2x80x94 are connected by way of spacer groups to in each case one reactive functional group. In the context of the present invention, the term xe2x80x9creactive functional groupxe2x80x9d refers to a group which, in contrast to an inert group, is readily available for further reactions. Accordingly, the group in question may comprise any desired group known from organic chemistry. In accordance with the invention, however, it is of advantage if it comprises a group of the general formula II.
xe2x80x94Xxe2x80x94Bxe2x80x83xe2x80x83(II)
In the general formula II, the variable xe2x80x94Xxe2x80x94 represents divalent oxygen and sulfur atoms or secondary amino groups. In accordance with the invention it is of advantage if the variable xe2x80x94Xxe2x80x94 represents divalent oxygen atoms.
In the general formula II, the variable B represents a hydrogen atom xe2x80x94H, a group xe2x80x94Z or a linear or branched group xe2x80x94R1xe2x80x94(xe2x80x94Z1)u, in which the index u=1 or 2.
Suitable groups xe2x80x94Z include all reactive functional groups of organic chemistry which under the customary and known conditions enter into reactions which lead to the desired further buildup of the compound of the invention or to its linking with other compounds, such as, for instance, with the crosslinkers known from the coating compositions or the adhesives. Examples of groups xe2x80x94Z which are particularly advantageous in accordance with the invention are:
xe2x80x94C(O)xe2x80x94NH2,
xe2x80x94C(O)xe2x80x94NHxe2x80x94C(O)xe2x80x94NH2,
xe2x80x94C(O)xe2x80x94OR2,
xe2x80x94C(O)xe2x80x94NHxe2x80x94C(O)xe2x80x94OR2,
xe2x80x94C(O)xe2x80x94CH2xe2x80x94C(O)xe2x80x94R2 
xe2x80x94C(O)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR2 
xe2x80x94C(O)xe2x80x94CR3=CH2, 
xe2x80x94Sixe2x80x94(OR4)3,
xe2x80x94(xe2x80x94CH2xe2x80x94)vxe2x80x94CHxe2x95x90CH2 and
xe2x80x94C(O)xe2x80x94(xe2x80x94CH2xe2x80x94)vxe2x80x94CHxe2x95x90CH2; in which the index v is 0 or is an integer from 1 to 3;
xe2x80x94C(O)xe2x80x94CHxe2x95x90CHxe2x80x94C(O)xe2x80x94Oxe2x80x94R2,
xe2x80x94C(O)xe2x80x94CHxe2x95x90CHxe2x80x94CHxe2x95x90CHxe2x80x94R2 and
xe2x80x94C(O)xe2x80x94CHxe2x95x90CHxe2x80x94CH2-CHxe2x95x90CHxe2x80x94R2.
In these formulae, the radicals R2 designate unsubstituted or substituted C1-C10 alkyl, C5-C10 cycloalkyl, C6-C20 cycloalkylalkyl, C6-C20 alkylcycloalkyl, C6-C10 aryl, C7-C20 arylalkyl, C7-C20 alkylaryl, C11-C26 arylcycloalkyl or C11-C26 cycloalkylaryl radical, the alkyl radicals being branched or unbranched.
Suitable substituents for these radicals R2 are all organic radicals which are substantially inert, i.e., which do not enter into reactions with the compounds which are used for the buildup of the compounds of the invention or for their further reaction. Examples of suitable inert organic radicals are halogen atoms, nitro groups, nitrile groups or alkoxy groups.
Examples of suitable unsubstituted or substituted C1-C10 alkyl radicals for use in accordance with the invention are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl or decyl radicals, of which the methyl, ethyl and propyl radicals are particularly advantageous and are therefore used with preference.
Examples of suitable unsubstituted or substituted C5-C10 cycloalkyl radicals for use in accordance with the invention are cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl or decalinyl radicals, of which the cyclopentyl and cyclohexyl radicals are advantageous and are therefore used with preference.
Examples of suitable unsubstituted or substituted C6-C20 cycloalkylalkyl radicals for use in accordance with the invention are cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl or cyclohexylpropyl radicals, of which the cyclohexylmethyl radical is advantageous and is therefore used with preference.
Examples of suitable unsubstituted or substituted C6-C20 alkylcycloalkyl radicals for use in accordance with the invention are 4-methylcyclohex-1-yl, 2-ethyl-cyclohex-1-yl or 4-methyl-2-ethylcyclohex-1-yl, of which the 4-methylcyclohex-1-yl radical is advantageous and is therefore used with preference.
Examples of suitable unsubstituted or substituted C6-C10 aryl radicals for use in accordance with the invention are phenyl or naphthyl radicals, of which the phenyl radicals are advantageous and are therefore used with preference.
Examples of suitable unsubstituted or substituted C7-C20 arylalkyl radicals for use in accordance with the invention are phenylmethyl, 2-phenylethyl or 3-phenylpropyl radicals, of which the 2-phenylethyl radicals are advantageous and are therefore used with preference.
Examples of suitable unsubstituted or substituted C7-C20 alkylaryl radicals for use in accordance with the invention are 2-, 3- and 4-methylphen-1-yl, 4-butylphen-1-yl, 4-butyl-2-methylphen-1-yl, 2,4-di-methylphen-1-yl or 4-octylphen-1-yl radicals, of which the 4-butylphen-1-yl or 4-octylphen-1-yl radicals are advantageous and are therefore used with preference.
Examples of suitable C11-C26 arylcycloalkyl radicals for use in accordance with the invention are 2- or 3-phenylcyclopent-1-yl or 2-, 3- or 4-phenylcyclohex-1-yl radicals, of which the 4-phenylcyclohex-1-yl radical is advantageous and is therefore used with preference.
Examples of suitable C11-C26 cycloalkylaryl radicals for use in accordance with the invention are 2-, 3- or 4-cyclopentylphen-1-yl or 2-, 3- or 4-cyclohexylphen-1-yl radicals, of which the 4-cyclohexylphen-1-yl radical is advantageous and is therefore used with preference.
The radicals R3 denote C1-C4-alkyl radicals or nitrile groups xe2x80x94CN. Examples of suitable C1-C4 alkyl radicals for use in accordance with the invention are methyl, ethyl, propyl or butyl radicals, of which the methyl radical is advantageous and is therefore used with preference.
The radicals R4 denote unsubstituted or substituted C1-C4 alkyl radicals; examples of suitable alkyl radicals of this type for use in accordance with the invention are those mentioned above. Examples of suitable substituents for use in accordance with the invention are those listed above in connection with the radicals R2.
The radical R1 of the linear or branched group xe2x80x94R1xe2x80x94(xe2x80x94Z1)u, in which the index u=1 or 2, comprises a divalent or trivalent radical which is derived from the following compounds:
(i) an alkane, alkene, cycloalkane, cycloalkene, alkylcycloalkane, alkylcycloalkene, alkenyl-cycloalkane, or alkenylcycloalkene, aromatics and heteroaromatics, and also an alkyl-, alkenyl-, cycloalkyl-, cycloalkenyl-, alkyl-cycloalkyl-, alkylcycloalkenyl-, alkenylcyclo alkyl- or alkenylcycloalkenyl-substituted aromatics or heteroaromatics; or
ii) an abovementioned radical which contains at least one heteroatom in the chain and/or in the ring; or
(iii) a radical mentioned under (i) or (ii) whose chain and/or ring is substituted.
Examples of suitable radicals R1 for use in accordance with the invention are the radicals (i1) to (iii2) listed below, of which the radicals (i2) to (i5) and also (i20) and (i21) are advantageous and are therefore used with particular preference. 
Examples of suitable substituents for use in accordance with the invention for the radicals R1 are those listed above in connection with the radicals R2.
As the variable Z1 of the linear or branched group xe2x80x94R1xe2x80x94(xe2x80x94Z1)u, in which the index u=1 or 2, suitable groups include all reactive functional groups of organic chemistry which under the customary and known conditions enter into reactions which lead to the desired further buildup of the compound of the invention or to its linking with other compounds, such as, for instance, with the crosslinkers known from the coating compositions or the adhesives. Examples of groups xe2x80x94Z1 which are particularly advantageous in accordance with the invention are:
xe2x80x94OH, xe2x80x94NH2, xe2x80x94SH,
xe2x80x94COOH, xe2x80x94SO3H, xe2x80x94PO3H
xe2x80x94Oxe2x80x94C(O)xe2x80x94NH2,
xe2x80x94Oxe2x80x94C(O)xe2x80x94NHxe2x80x94C(O)xe2x80x94NH2,
xe2x80x94NCO;
xe2x80x94NHxe2x80x94C(O)xe2x80x94OR2,
xe2x80x94NHxe2x80x94C(O)xe2x80x94NHxe2x80x94C(O)xe2x80x94OR2,
xe2x80x94Oxe2x80x94C(O)xe2x80x94CH2xe2x80x94C(O)xe2x80x94R2,
xe2x80x94Oxe2x80x94C(O)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR2 
xe2x80x94Oxe2x80x94C(O)xe2x80x94CR3=CH2; 
xe2x80x94Oxe2x80x94Sixe2x80x94(OR4)3,
xe2x80x94Oxe2x80x94(xe2x80x94CH2xe2x80x94)vxe2x80x94CHxe2x95x90CH2 and
xe2x80x94Oxe2x80x94C(O)xe2x80x94(xe2x80x94CH2xe2x80x94)vxe2x80x94CHxe2x95x90CH2; in which the index v is 0 or an integer from 1 to 3, but in particular 0 and 1;
xe2x80x94Oxe2x80x94C(O)xe2x80x94CHxe2x95x90CHxe2x80x94C(O)xe2x80x94Oxe2x80x94R2,
xe2x80x94Oxe2x80x94C(O)xe2x80x94CHxe2x95x90CHxe2x80x94CHxe2x95x90CHxe2x80x94R2 and
xe2x80x94Oxe2x80x94C(O)xe2x80x94CHxe2x95x90CHxe2x80x94CH2xe2x80x94CHxe2x95x90CHxe2x80x94R2.
The reactive functional groups of the general formula II that are described in detail above are, in accordance with the invention, connected to the central group I by way of spacer groups.
Suitable spacer groups in accordance with the invention are all divalent organic radicals.
Examples of highly suitable divalent organic radicals are the divalent radicals R1 described above, but especially the radical (i5).
Further examples of highly suitable divalent organic radicals for use in accordance with the invention are the spacer groups (iv1) to (iv8) listed below. Regarding their preparability and the advantageous properties which they impart to the compounds of the invention, these spacer groups have particular advantages, and so are used with preference. Of the spacer groups (iv1) to (iv8), the spacer groups (iv1) and (iv7) are especially advantageous and are therefore used with very particular preference. 
in which the index w=an integer from 1 to 10.
In the general formulae IVA and IVB, the radical R2 is as defined above. The carbonyloxy substituents of the rings in the general formulae IVA are positioned 1,2 (spacer group iv1), 1,3 (spacer group iv2) or 1,4 (spacer group iv3) with respect to one another. The carbonyloxy substituents of the rings in the general formulae IVB are likewise positioned 1,2 (spacer group iv4), 1,3 (spacer group iv5) or 1,4 (spacer group iv6) with respect to one another.
In the formulae of the spacer groups (iv1) to (iv10) the radical R5 denotes alkyl, cycloalkyl or aryl ether or alkyloxy, cycloalkyloxy or arylcarbonyloxy radicals, but especially tertiary alkylcarbonyloxy radicals. Particular examples of suitable radicals R5 for use in accordance with the invention are VersaticR acid radicals, i.e., radicals of tertiary, highly branched monocarboxylic acids.
In accordance with the invention, the reactive functional group II described in detail above is linked with the spacer groups (iv1) to (iv10) by way of the secondary carbon atom.
The especially advantageous compounds of the invention have the particular advantage that their hydroxyl groups may be converted into other reactive functional groups II in an extraordinary variety of ways. Examples of such reactive functional groups II are the above-described groups xe2x80x94Z. They may be prepared, for example, by reacting the hydroxyl groups with the following compounds:
R2Oxe2x80x94C(O)xe2x80x94NH2,
R2Oxe2x80x94C(O)xe2x80x94NHxe2x80x94C(O)xe2x80x94NH2,
Clxe2x80x94C(O)xe2x80x94OR2,
Clxe2x80x94C(O)xe2x80x94NHxe2x80x94C(O)xe2x80x94OR2,
Clxe2x80x94C(O)xe2x80x94CH2xe2x80x94C(O)xe2x80x94R2 
Clxe2x80x94C(O)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR2 
HOxe2x80x94C(O)xe2x80x94CR3xe2x95x90CH2, 
Clxe2x80x94Sixe2x80x94(OR4)3,
Clxe2x80x94(xe2x80x94CH2xe2x80x94)vxe2x80x94CHxe2x95x90CH2 and
Clxe2x80x94C(O)xe2x80x94(xe2x80x94CH2xe2x80x94)vxe2x80x94CHxe2x95x90CH2; in which the index v is 0 or is an integer from 1 to 3, but in particular is 0 and 1;
Clxe2x80x94C(O)xe2x80x94CHxe2x95x90CHxe2x80x94C(O)xe2x80x94Oxe2x80x94R2,
Clxe2x80x94C(O)xe2x80x94CHxe2x95x90CHxe2x80x94CHxe2x95x90CHxe2x80x94R2 and
Clxe2x80x94C(O)xe2x80x94CHxe2x95x90CHxe2x80x94CH2xe2x80x94CHxe2x95x90CHxe2x80x94R2.
In these formulae, the indices and the variables are as defined above.
Moreover, the especially advantageous compounds of the invention which contain the spacer groups (iv7) and (iv8) have the very particular advantage that they can be modified on their olefinic double bond, so that besides the reactive functional groups II they may also contain further reactive functional groups. One example of such a modification is the addition of amines onto the double bonds.
Examples of especially advantageous compounds of the invention are, accordingly, the compounds (I1) to (I3). 
The compounds of the invention may be prepared by the customary and known methods of preparing hyperbranched and dendrimeric compounds. Suitable synthesis methods are described, for example, in the patents WO 93/17060 or WO 96/12754 or in the book by G. R. Newkome, C. N. Moorefield and F. Vxc3x6gtle, xe2x80x9cDendritic Molecules, Concepts, Syntheses, Perspectivesxe2x80x9d, VCH, Weinheim, N.Y., 1996. The skilled worker is therefore easily able to select suitable starting compounds based on the desired structures of the compounds of the invention.
It is substantial to the invention to prepare the central group I or the compound of the invention using a tetrafunctional compound of the general formula III
xe2x80x83C[xe2x80x94Aqxe2x80x94XH]m[xe2x80x94Arxe2x80x94XH]n[xe2x80x94Asxe2x80x94XH]o[xe2x80x94Atxe2x80x94XH]pxe2x80x83xe2x80x83(III).
In the text below, this compound is referred to for brevity as xe2x80x9ccompound IIIxe2x80x9d.
In the general formula III, the indices and variables are as defined above for the general formula I. In accordance with the invention it is of particular advantage if the variable X represents an oxygen atom xe2x80x94Oxe2x80x94.
Accordingly, the tetrols of the general formula III are of particular advantage, and are therefore used with particular preference, for the preparation of the central group I and, respectively, of the compounds of the invention. In the text below these tetrols are referred to for brevity as xe2x80x9ctetrols IIIxe2x80x9d.
Examples of especially suitable tetrols III for use in accordance with the invention are the tetrols (III1) to (III10):
HOxe2x80x94(xe2x80x94CH2xe2x80x94)2xe2x80x94C(xe2x80x94CH2xe2x80x94OH)3, (III1)
HOxe2x80x94(xe2x80x94CH2xe2x80x94)3xe2x80x94C(xe2x80x94CH2xe2x80x94OH)3, (III2)
HOxe2x80x94(xe2x80x94CH2xe2x80x94)4xe2x80x94C(xe2x80x94CH2xe2x80x94OH)3, (III3)
HOxe2x80x94(xe2x80x94CH2xe2x80x94)5xe2x80x94C(xe2x80x94CH2xe2x80x94OH)3, (III4)
[HOxe2x80x94(xe2x80x94CH2xe2x80x94)2xe2x80x94]2C(CH2xe2x80x94OH)2, (III5)
[HOxe2x80x94(xe2x80x94CH2xe2x80x94)2xe2x80x94]3Cxe2x80x94CH2xe2x80x94OH, (III6)
HOxe2x80x94(xe2x80x94CH2xe2x80x943xe2x80x94C[xe2x80x94(xe2x80x94CH2xe2x80x94)2xe2x80x94OH]3, (III7)
HOxe2x80x94(xe2x80x94CH2xe2x80x94)3xe2x80x94C[xe2x80x94(xe2x80x94CH2xe2x80x94)2xe2x80x94OH]2(xe2x80x94H2xe2x80x94OH), (III8)
HOxe2x80x94(xe2x80x94CH2xe2x80x94)4xe2x80x94C(xe2x80x94CH2xe2x80x94OH)[xe2x80x94(xe2x80x94CH2xe2x80x94)2xe2x80x94OH][xe2x80x94(xe2x80x94CH2xe2x80x94)3xe2x80x94OH] or (III9)
HOxe2x80x94(xe2x80x94CH2xe2x80x94)5xe2x80x94C(xe2x80x94CH2xe2x80x94OH)[xe2x80x94(xe2x80x94CH2xe2x80x94)4xe2x80x94OH]2 (III10).
Of these, particular attention is drawn to the tetrol (III1) (2,2-bishydroxymethyl-1,4-butanediol; homopentaerythritol), since it imbues the compounds of the invention with especially advantageous properties. It is therefore used with very particular preference.
In accordance with a first variant, the procedure of the invention results in the reactive functional groups II and thus the compounds of the invention from the reaction of the compounds III, in particular the tetrols III, with suitable organic compounds in one stage.
Suitable organic compounds are all compounds which first carry functional groups which are able to react with the groups -XH described in detail above and second introduce the divalent radicals R1 described in detail above into the intermediate.
Examples of suitable organic compounds for use in accordance with the invention are, accordingly, the divalent radicals R1 described in detail above which carry, in particular, the following functional groups:
xe2x80x94NCO,
xe2x80x94Cl,
xe2x80x94Br,
xe2x80x94C(O)xe2x80x94Cl,
xe2x80x94C(O)xe2x80x94Br,
xe2x80x94C(O)xe2x80x94OH or
xe2x80x94C(O)xe2x80x94Oxe2x80x94C(O)xe2x80x94.
Of these, the carboxyl groups and the anhydride groups are of particular advantage and are therefore used with particular preference.
It is therefore simple for the skilled worker to select the appropriate organic compounds for use in accordance with the invention on the basis of the desired target structure of the compound of the invention.
In a second variant, by the procedure of the invention, it is possible first to prepare an intermediate containing the central group I and four spacer groups from the compounds III, especially the tetrols III, and an appropriate organic compound. The appropriate organic compound is chosen so that the resulting spacer groups each carry one reactive functional group. In a second stage, these reactive functional groups are reacted with a suitable organic compound to form the reactive functional groups II and thus the compounds of the invention. In accordance with the invention, preference is given to this variant.
Examples of suitable organic compounds are the compounds listed above in connection with the first variant.
Examples of suitable reactive functional groups are the functional groups listed above in connection with the first variant.
Examples of organic compounds which are suitable for this variant are epsilon-caprolactone, hexahydro-phthalic acid, hexahydrophthalic anhydride, phthalic acid, phthalic anhydride, hexahydroterephthalic acid, terephthalic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, oxalic acid, malonic acid, malonic anhydride, succinic acid, succinic anhydride, glutaric acid, glutaric anhydride, adipic acid, adipic anhydride, pimelic acid, suberic acid, azelaic acid, sebacic acid or decane-, undecane- or dodecanedicarboxylic acid. Of these, epsilon-caprolactone, maleic acid or maleic anhydride and hexahydrophthalic anhydride are especially suitable and are therefore used with particular preference in accordance with the invention.
Examples of highly suitable organic compounds which may be reacted in the second stage with the intermediate to form the reactive functional groups II and thus the compounds of the invention are compounds containing epoxide groups, especially compounds containing glycidyl groups.
Examples of suitable compounds containing epoxide groups, especially compounds containing glycidyl groups, are ethylene oxide, propylene oxide, epichlorohydrin, glycidol, glycidyl ethers, especially aryl and alkyl glycidyl ethers, or glycidyl esters, especially the glycidyl esters of tertiary, highly branched, saturated monocarboxylic acids, which are sold under the trade name VersaticR acids by the company Deutsche Shell Chemie. Of these, the VersaticR acid glycidyl esters, which are sold under the trade name CarduraR E10, are especially advantageous and are therefore used with very particular preference.
Further examples of highly suitable organic compounds which may be reacted in the second stage with the intermediate to form the reactive functional groups II and thus the compounds of the invention are acrylic acid and methacrylic acid.
All variants of the process of the invention may be conducted in solution or in bulk. Depending on the reactants present, it is possible to operate under pressure. In general, the appropriate reaction temperatures are from xe2x88x9250 to +300xc2x0 C., preferably from 0 to 250xc2x0 C., more preferably from room temperature to 200xc2x0 C. and in particular from 60 to 160xc2x0 C. The reaction conditions that are particularly suitable in each case may easily be selected by the skilled worker on the basis of the properties of the reactants.
The compounds of the invention, especially those prepared in the manner of the process of the invention, have particular advantages. In numerous end uses they are superior to the known hyperbranched compounds and dendrimers, so that they may be used very much more widely than the latter.
For instance, they permit the preparation of new dendrimers of higher generations in a simple way.
In particular, the compounds of the invention make it possible, very generally, to prepare multisubstance mixtures of the invention which are liquid, solid or dispersed or dissolved in aqueous or organic media, and which have new advantageous profiles and performance properties. For instance, the compounds of the invention are used to obtain sealing compounds, adhesives or coating compositions, in dispersion or solution in aqueous or organic media, which have particularly high solids contents. Furthermore, powder coating materials and powder slurries of the invention possess advantageously low film formation temperatures, which are not too close to the crosslinking temperature. Additionally, the coating compositions of the invention are suitable for the production of films, especially self-supporting paint films.
The coating compositions, adhesives and sealing compounds of the invention may be air drying, physically drying, thermally curable, curable with actinic light, and/or curable with electron beams. In this context, the thermally curable coating compositions, adhesives and sealing compounds of the invention have particular advantages.
The coating compositions of the invention may comprise
in solution or dispersion in aqueous or organic media
spray coating materials, liquid coating materials, powder coating materials or powder slurries. These are outstandingly suitable for all end uses to which coating materials are commonly put. In particular, they are suitable as coating materials for the industrial sector, furniture coatings, architectural coatings, automotive OEM coating materials, or automotive refinish coating materials.
Very particular advantages are possessed by the coating compositions of the invention comprising compounds of the invention containing hydroxyl groups as reactive functional groups II.
Besides the compounds of the invention, the coating compositions of the invention, of the type specified above, comprise binders which likewise contain hydroxyl groups.
Suitable hydroxy-functional binders are preferably binders based on polyacrylates, polyesters, polyurethanes, acrylated polyurethanes, acrylated polyesters, polylactones, polycarbonates, polyethers and/or (meth)acrylatediols. Hydroxy-functional binders are known to the skilled worker, and numerous suitable examples are available commercially.
Preference is given to the use of polyacrylates, polyesters and/or polyurethanes. Examples of binders of this kind that are used with particular preference are:
1. Polyacrylates having a hydroxyl number of from 40 to 240, preferably from 60 to 210, in particular from 100 to 200, an acid number of from 0 to 35, glass transition temperatures of from xe2x88x9235 to 85xc2x0 C., and number-average molecular weights Mn of from 1 500 to 300 000.
The glass transition temperature of the polyacrylates is determined, as is known, by the nature and amount of the monomers used. The selection of the monomers may be made by the skilled worker with assistance from the following formula V, by which the glass transition temperatures may be calculated approximately.                                           1            /            Tg                    =                                    ∑                              n                =                1                                            n                =                x                                      ⁢                          xe2x80x83                        ⁢                                          W                n                            /                              Tg                n                                                    ;                                            ∑              n                        ⁢                          W              n                                =          1                                    (        V        )            
Tg=Glass transition temperature of the polyacrylate resin
Wn=Weight fraction of the nth monomer
Tgn=Glass transition temperature of the homopolymer of the nth monomer
x=Number of different monomers
Measures to control the molecular weight (e.g., selection of appropriate polymerization initiators, use of chain transfer agents or of special techniques of polymerization, etc.) belong to the art and need not be elucidated in any more detail here.
1.1 Particularly preferred polyacrylates are preparable by polymerizing (a1) from 10 to 92, preferably from 20 to 60% by weight of an alkyl or cycloalkyl methacrylate having 1 to 18, preferably 4 to 13, carbon atoms in the alkyl or cycloalkyl radical, or mixtures of such monomers, (a2) from 8 to 60, preferably from 12.5 to 50.0% by weight of a hydroxyalkyl acrylate or hydroxyalkyl methacrylate having 2 to 4 carbon atoms in the hydroxyalkyl radical, or mixtures of such monomers, (a3) from 0 to 5, preferably from 0.7 to 3% by weight of acrylic acid or methacrylic acid or mixtures of these monomers and (a4) from 0 to 50, preferably up to 30% by weight, of ethylenically unsaturated monomers different than but copolymerizable with (a1), (a2) and (a3), or mixtures of such monomers, (a4), to give polyacrylates of the specification indicated above.
Examples of suitable (a1) components are methyl, ethyl, propyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl or 2-ethylhexyl acrylate or methacrylate and also cyclohexyl, tert-butyl-cyclohexyl or isobornyl acrylate or methacrylate.
Examples of suitable (a2) components are hydroxyethyl, hydroxypropyl or hydroxybutyl or hydroxy-methylcyclohexyl acrylate or methacrylate or adducts of (meth)acrylic acid and epoxides such as Versatic acidR glycidyl esters.
Example of suitable (a4) components are vinyl-aromatics such as styrene, vinyltoluene, alpha-methylstyrene, alpha-ethylstyrene, ring-substituted diethylstyrenes, isopropylstyrene, butylstyrene and methoxystyrenes; vinyl ethers such as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether or isobutyl vinyl ether; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate or the vinyl ester of 2-methyl-2-ethylheptanoic acid; or allyl ethers such as trimethylolpropane monoallyl, diallyl or triallyl ether or ethoxylated or propoxylated allyl alcohol.
1.2 Further examples of particularly preferred polyacrylates are described in the European patent application EP-A-0 767 185 and in the American patents U.S. Pat. No. 5,480,493, 5,475,073 or 5,534,598.
1.3 Further examples of particularly preferred polyacrylates are sold under the brand name JoncrylR, such as JoncrylR SCX 912 and 922,5, for instance.
1.4 Further examples of particularly preferred polyacrylates are those obtainable by polymerizing (a1) from 10 to 51% by weight, preferably from 25 to 41% by weight, of 4-hydroxy-n-butyl acrylate or methacrylate or a mixture thereof, but especially 4-hydroxy-n-butyl acrylate, (a2) from 0 to 36% by weight, preferably from 0.1 to 20% by weight, of a non-(a1) hydroxyl-containing ester of acrylic acid or of methacrylic acid, or a mixture thereof, (a3) from 28 to 85% by weight, preferably from 40 to 70% by weight, of an aliphatic or cycloaliphatic ester of methacrylic acid having at least four carbon atoms in the alcohol residue and being different than (a1) and (a2), or a mixture of such monomers (a3), (a4) from 0 to 3% by weight, preferably from 0.1 to 2% by weight, of an ethylenically unsaturated carboxylic acid or a mixture of such acids, and (a5) from 0 to 20% by weight, preferably from 5 to 15% by weight, of an unsaturated monomer different than (a1), (a3) and (a4), or a mixture of such monomers (a5), to give a polyacrylate having a hydroxyl number of from 60 to 200, preferably from 100 to 160, an acid number of from 0 to 35 and a number-average molecular weight Mn of from 1 500 to 10 000, the composition of component (a3) being chosen so that polymerization of this component (a3) alone gives a polymethacrylate having a glass transition temperature of from +10 to +100xc2x0 C., preferably from +20 to +60xc2x0 C.
Examples of suitable components (a2) are hydroxyalkyl esters of acrylic acid and methacrylic acid such as hydroxyethyl or hydroxypropyl acrylate or methacrylate, the choice being made such that polymerization of this component (a2) alone gives a polyacrylate having a glass transition temperature of from 0 to +80xc2x0 C., preferably from +20 to +60xc2x0 C.
Examples of suitable components (a3) are aliphatic esters of methacrylic acid having 4 to 20 carbon atoms in the alcohol residue, such as n-butyl, isobutyl, tert-butyl, 2-ethylhexyl, stearyl and lauryl methacrylate; or cycloaliphatic esters of methacrylic acid such as cyclohexyl methacrylate. Examples of suitable components (a4) are acrylic acid and/or methacrylic acid.
Examples of suitable components (a5) are vinylaromatic hydrocarbons such as styrene, alpha-alkylstyrene or vinyltoluene; amides of acrylic acid and methacrylic acid such as methacrylamide and acrylamide; nitrites of acrylic acid and methacrylic acid; vinyl ethers or vinyl esters, the composition of this component (a5) preferably being such that polymerization of components (a5) alone results in a polyacrylate having a glass transition temperature of from +70 to +120xc2x0 C., in particular from +80 to +100xc2x0 C.
1.5 The preparation of these polyacrylates is common knowledge and is described, for example, in the standard work Houben-Weyl, Methoden der organischen Chemie, 4th edition, volume 14/1, pages 24 to 255, 1961.
2. Polyester resins preparable by reacting (a1) at least one cycloaliphatic or aliphatic polycarboxylic acid, (a2) at least one aliphatic or cycloaliphatic polyol having more than two hydroxyl groups in the molecule, (a3) at least one aliphatic or cycloaliphatic diol, and (a4) at least one aliphatic, linear or branched saturated monocarboxylic acid, in a molar ratio of (a1):
(a2): (a3): (a4)=1.0: 0.2 to 1.3: 0.0 to 1.1: 0.0 to 1.4, preferably 1.0: 0.5 to 1.2: 0.0 to 0.6: 0.2 to 0.9, to give a polyester or alkyd resin.
Examples of suitable components (a1) are hexahydrophthalic acid, 1,4-cyclohexane-dicarboxylic acid, endomethylenetetrahydrophthalic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid or sebacic acid.
Examples of suitable components (a2) are pentaerythritol, trimethylolpropane, triethylolethane and glycerol.
Examples of suitable components (a3) are ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, 2-methyl-2-propyl-1,3-propane-diol, 2-methyl-2-butyl-1,3-propanediol, 2,2,4-tri-methyl-1,5-pentanediol, 2,2,5-trimethyl-1,6-hexanediol, neopentyl glycol hydroxypivalate or dimethylolcyclohexane.
Examples of suitable components (a4) are 2-ethylhexanoic acid, lauric acid, isooctanoic acid, isononanoic acid or monocarboxylic acid mixtures obtained from coconut oil or palm kernel oil.
The preparation of the polyesters and alkyd resins used with preference in accordance with the invention is common knowledge and is described, for example, in the standard work Ullmanns Enklopxc3xa4die der technischen Chemie, 3rd Edition, volume 14, Urban and Schwarzenberg, Munich, Berlin, 1963, pages 80 to 89 and pages 99 to 105, and also in the following books: xe2x80x9cRxc3xa9sines Alkydes-Polystersxe2x80x9d by J. Bourry, Paris, Dunod, 1952, xe2x80x9cAlkyd Resinsxe2x80x9d by C. R. Martens, Reinhold Publishing Corporation, New York, 1961, and xe2x80x9cAlkyd Resin Technologyxe2x80x9d by T. C. Patton, Interscience Publishers, 1962.
3. Polyurethanes as described in the patents EP-A-0 708 788, DE-A-44 01 544 or DE-A-195 34 361.
To further increase the solids content, a portion of the binders may be replaced by reactive diluents. Examples of suitable reactive diluents are branched, cyclic and/or acyclic C9-C16 alkanes functionalized with at least two hydroxyl or thiol groups or at least one hydroxyl and at least one thiol group, especially diethyloctanediols.
Further examples of suitable reactive diluents are oligomeric polyols obtainable from oligomers, which are obtained by metathesis reactions of acyclic monoolefins and cyclic monoolefins, by hydroformylation and subsequent hydrogenation; examples of suitable cyclic monoolefins are cyclobutene, cyclopentene, cyclohexene, cyclooctene, cycloheptene, norbornene or 7-oxa-norbornene; examples of suitable acyclic monoolefins are present in hydrocarbon mixtures which are obtained in petroleum processing by cracking (C5 cut); examples of suitable oligomeric polyols for use in accordance with the invention have a hydroxyl number (OHN) of from 200 to 450, a number-average molecular weight Mn of from 400 to 1 000 and a mass-average molecular weight Mw of 600 to 1 100;
Furthermore, the coating compositions of the invention comprise crosslinkers, which enter into crosslinking reactions with the hydroxyl groups in the compounds of the invention and in the binders and also, if appropriate, in the reactive diluents.
Resins suitable for this purpose are the customary and known amino resins whose methylol and/or methoxymethyl groups may have been partly defunctionalized by means of carbamate or allophanate groups. Crosslinkers of this kind are described in the patents U.S. Pat. No. 4,710,542 and EP-B-0 245 700 and also in the article by B. Singh and coworkers, xe2x80x9cCarbamylmethylated Melamines, Novel Crosslinkers for the Coatings Industryxe2x80x9d in Advanced Organic Coatings Science and Technology Series, 1991, volume 13, pages 193 to 207.
Besides these crosslinkers, further crosslinkers may also be present. Examples of suitable further crosslinkers are resins or compounds containing siloxane groups, resins or compounds containing anhydride groups, resins or compounds containing epoxide groups, blocked and/or unblocked, monomeric and/or oligomeric polyisocyanates, and/or tris(alkoxy-carbonylamino)triazines, as are described in the patents U.S. Pat. No. 4,939,213, U.S. Pat. No. 5,084,541, U.S. Pat. No. 5,288,865 or EP-A-0 604 922.
The viscosity of the crosslinkers is generally between 10 and 20 000 mPas. Its functionality is normally between 1 and 5, in particular 1.5 and 4.5.
Depending on the reactivity of the further crosslinker, it may be added directly to the coating compositions of the invention to give what is known as a one-component system. If it is a particularly reactive crosslinker, such as a polyisocyanate or an epoxide, it is generally not added to the coating compositions of the invention until shortly before use. This results in what is known as a two-component or multicomponent system, as are known in particular from the automotive refinish sector.
The coating compositions of the invention may comprise customary and known additives in customary and known, effective amounts.
Examples of suitable additives are polymers, crosslinkers, crosslinking catalysts, initiators, especially photoinitiators, pigments, dyes, fillers, reinforcing fillers, rheological assistants, solvents, wetting agents, dispersants, defoamers, adhesion promoters, additives for improving substrate wetting, additives for improving surface smoothness, flatting agents, leveling agents, film forming auxiliaries, dryers, antiskimming agents, light stabilizers, corrosion inhibitors, biocides, flame retardants, polymerization inhibitors, especially photoinhibitors, or plasticizers, as are customary and known, for example, in the plastics or coatings sector.
The selection of the additives is guided by the desired profile of properties of the coating compositions, adhesives and sealing compounds of the invention and by their specific end uses and may therefore be made by the skilled worker in a simple manner, possibly with the assistance of simple preliminary tests.